Terminal for electrical conductors



c. D. LAKE TEl ZMINAL FOR ELECTRICAL CONDUCTORS Oct. 6, 1942.

Filed Sept. 13, 1941 '2 I W /3\ n 0;, m a I i F |G.4-.

Patented Oct. 6, 1942 TERMINAL FOR ELECTRICAL CONDUCTORS Clair DQLake, Binghamton, N. Y., assignor to International Business Machines Corporation, New York, Y., a corporation of New York Application September 13, 1941, Serial No. 410,703

Claims.

-By employing this method of affixing a terminal to an insulated conductor, it is readily understood that varying types and sizes of swaging implements are necessary for different types of terminals, particularly those terminals having differently shaped nose portions.

The present invention contemplates simplifying the procedure of swaging terminals to the electrical conductors by employing a novel swage connection therebetween, and consequently reducing the cost and material factors involved in This end is attained by prothis procedure. viding an elongated cylindrically shaped skirt portion on each terminal and forming thereon two swaged polygonal sections which are adjacent to and separated by a non-swaged section, the said nonswaged section being disposed in a predetermined and definite relationship with respect to the tapering section connecting the axial recesses or bores of dissimilar diameters which are formed in the said skirt portion.

It has been determined by experiment that this non-swaged section of a terminal has a dellnite and most important function and purpose by reducing the tensile strains setup within the electrical conductor during the process of swaging or deforming the skirt portion of the terminal, and, by permitting the conductor insulation to enter and expand in this non-swaged section, thus, insuring a sealed connection between vthe conductor and terminal, and increasing the tensile strength of the connection therebetween.

Therefore, another object of the present invention resides in the provision of a terminal which is connected to an insulated conductor by two identical swaged sections formed on the skirt portion of the terminal, which sections are separated by a non-swaged portion, the latter being disposed so as to surround solely the tapering section of the terminal connecting the larger axial bore with the smaller axial bore and a portion of the adjoining larger axial bore, thereby providing a non-swaged portion substantially less' in length than either of the adjoining swag sections.

Other objects of the invention will be pointed out in the following description and claims and illustrated 'in the accompanying drawing, which discloses by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawing:

Fig. 1 is a side view partly in section and partly in elevation, showing a terminal applied to an electrical conductor prior to the swaging thereto.

Figs. 2 and 3 are transverse sectional views of the terminal and conductor positioned in a pair of swaging dies, at the beginning and at the end. respectively, of the swaging operation.

Fig. 4 is a side elevational view showing the terminal after the swaging operations have been completed.

Fig. 5 is a sectional view taken along the line 55 of Fig. 4.

Fig. 6 is a side elevational view of another type of terminal before being swaged to a conductor.

Fig. 7 is a similar side elevational view of the terminal in Fig. 6 after the swaging operations have been completed.

Figs. 8 and 9 are side elevational views of still another type of terminal before and after, respectively, the swaging operations.

Fig. 10 is a side elevational view of a swaged terminal showing a modification of the swage connection.

Fig. 11 is a sectional view taken along the lines ll-l| in Fig. 10.

Referring now to Fig. 1 wherein one type of a suitable electrically conductive terminal T is shown to comprise a nose portion l2 and a skirt portion lit, the diameter of the latter being less than the mean diameter of the former; said skirt portion l3 having an initially cylindrical shaped outer surface of uniform diameter throughout its entire length, whereas the nose portion [2 is tapered slightly towards the tip or exploring end of the terminal. The terminal is shown as having a smaller axial bore or recess l4 formed in part of the skirt portion l3 and extending partially into the nose portion l2, and a larger axial bore or recess I5 formed in the remaining part of the said skirt portion. The said bores or recesses of dissimilar diameters are connected together by a tapering or conical wall section l6. It is to be noted that the said axial bores are disposed in the skirt portion so that this said tapering or conical connecting section is also formed and disposed in the said skirt portion 13 of the terminal. The said terminalis designed to be mounted on an electrical conductor C comprising an inner core ll of current conducting material, preferably stranded wire as shown, and an outer covering of suitable insulating material l8. As shown in Fig. l, the insulation is removed from one end of the conductor to provide a bared portion of-the conducting material. The insulation is removed from the conductor to a distance from the end thereof that is less than the combined length of the smaller axial bore [4 and the conical wall section IS. The axial bore I4 is slightly greater in diameter than the core of conducting material l1, and the axial bore I5 is slightly greater in diameter than the insulated portion of the conductor, so that the bared conductor can readily be inserted into the terminal.

With the terminal T positioned on the prepared extremity of the insulated conductor C, the bared conducting material H is received in the bore H and the insulation I8 in the enlarged bore 15. The shoulder formed by removing the insulation from the conducting member may abut the wall of the tapered portion l6 as shown, so as to serve as a suitable means for limiting the insertion of the conductor.

With the terminal positioned on the conductor as described, the assembly is placed in a suitable device for effecting a swaged connection therebetween. In this step of the method, the terminal of the said assembly is engaged by a pair of mating compression dies l9. It is seen that these dies are provided with complementary recesses 20 in their opposed faces which are adapted to deform the terminal into the desired shape. In compressing the cylindrical skirt so as to firmly secure the terminal to the insulated section of the conductor, and to cause an intimate contact of the terminal and the bared end of the conductor, the skirt portion is preferably deformed from an initial cylindrical shape into a generally polygonal cross-sectional shape, and more specifically, a hexagonal cross-sectional shape. It is evident that the compression force can be applied to one of the dies, as indicated in Fig. 2, or if desired can be applied to both of the dies.

With reference also to Figs. 4 and 5, it is seen that the dies l9 are provided with complementary recesses in their opposed faces which are adapted to deform the cylindrically shaped skirt portion into two hexagonally shaped sections A and B, which sections are adjacent to and separated by a non-swaged section D. The widths of the hexagonal recesses in the dies are preferably slightly larger than the initial diameter of the skirt portion. It has -been found that this relationship of the size of the hexagonal section and the initial cylindrical section ishighly desirable in order to ensure sufficient gripping pressure upon the conductor without damaging or severing the bored end of the conductor. When swaging terminals to conductors having relatively small diameters, such as No. 20 to 24 gauge conductors, the last mentioned provision is of utmost importance.

The terminal assembly is placed and positioned in the dies l9 so that the non-swaged section D is disposed so as to surround solely the tapering section I6 connecting the axial bores I4 and I5 and a portion of the adjoining larger axial bore. Thus, during the swaging process, the tensile strains set up within the electrical conductor are reduced, and as mentioned hereinbefore, the conductor insulation is permitted to expand into this non-swaged section and effect a sealed bond between the terminal and conductor, thereby enhancing the mechanical bond and conductive connection therebetween. As indicated in Fig. 4 the swaged section A is adapted to grip the insulated portion of the conductor C, and the swaged section B is adapted to grip the bared end of the said conductor so as to produce an intimate conductive connection between the two; also, as indicated in Fig. 4, the two swaged sections are identical and are separated by a nonswaged section substantially less in length than either of the adjoining swaged sections.

In Figs. 6 and 7 another type of terminal TI is shown comprising a tapered nose portion l2 and a skirt portion I3 cylindrically shaped throughout its entirety, the diameter of the latter being greater than the larger diameter of the former. A smaller axial bore [4 is provided in part of the skirt portion and extending partially into the said nose portion. A larger axial bore I5 is also provided in the skirt portion which is connected to the smaller bore by the tapering section H5. The terminal TI is swaged to the conductor Cl precisely as described hereinabove to produce the two swaged sections A and B which are adjacent to and separated by the nonswaged section D, the latter being formed or disposed so as to surround the said tapering wall section l6 as described hereinabove.

In Figs. 8 and 9 still another type of terminal T2 is shown to comprise a cylindrically shaped skirt and nose portions designated l2 and .I3, respectively. The diameter of the skirt portion is greater than that of the nose portion. In the said nose portion, a locking ferrule 25 is provided. The terminal is swaged as described to the conductor C2 so that the two swaged sections A and B which are adjacent to and separated by the non-swaged section D are formed on the skirt portion I 3. As mentioned before the non-swaged section D is disposed in the skirt portion so as to surround the tapering section l6 interconnecting the smaller and larger bores I4 and I5, respectively, as described hereinabove.

In Figs. 10 and 11, the terminal Tl shown in Figs. 6 and 7 is provided with the described swage connection, and in addition thereto is provided with another swaged section E whereby the bared end of the conductor Cl is brought into intimate contact with the nose portion of the terminal. In certain applications, it may be desirable to provide this type of additional swaged connection.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention.

It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

drically shaped skirt portion having two identical swaged sections formed thereon, which sections are adjacent to and separated by a nonswaged section, the latter section being disposed so as to surround solely the said tapering wall section interconnecting the said axial bores and a portion of the adjoining larger axial bore thereby providing a non-swaged section substantially less in length than either of the adjoining swaged sections.

2. An electrical connection comprising an insulated electrical conductor, the insulation on said conductor terminating short of the end of the conductor, leaving the end portion of the conductor bare, a terminalfor said conductor having a nose portion and a skirt portion, said skirt portion having an initially cylindrical shaped outer surface of uniform diameter throughout its entire length and provided with an axial bore receiving the bared end portion of the conductor and a larger axial bore receiving the insulated portion of the conductor, said bores be' interconnected by a tapering wall section, said skirt portion of the terminal and both the bared and insulated portions of the conductor being swaged together into a continuous connection, the said swage connection e0mprising two identical swaged polygonally shaped sections which are adjacent to and separated by a non-swaged section, the latter being disposed so as to surround solely the said tapering wall section and a portion of the adjoining larger axial bore thereby providing a non-swaged section substantially less in length than either of the adjoining swaged sections.

3. An electrical connection comprising an insulated electrical conductor, the insulation on said conductor terminating short of the end of the conductor leaving the end portion of the conductor bare, a terminal for said conductor and both the bared and insulated portions of the conductor being swaged together into a continuous connection, the said swage connection comprising two identical swaged hexagonally shaped sections which are adjacent to and separated by a non-swaged section, the latter being disposed so as to surround solely the said tapering wall section and a portion of the adjoining larger axial bore thereby providing a non-swaged section substantially less in length than either of the adjoining swaged sections.

4. An electrical connection comprising an insulated electrical conduct-or, the insulation on said conductor terminating short of the end of the conductor leaving the end portion of the conductor bare, a terminal for said conductor having a nose portion and a skirt portion, said skirt portion having an initially cylindrical shaped outer surface ofuniform diameter throughout its entire length and provided with an axial bore extending into the said nose portion receiving the bared end portion of the con doctor and a larger axial bore receiving the insulated portion of the conductor, said bores being interconnected by a tapering wall section, said skirt portion of the terminal and both the bared and insulated portions of the conductor being swaged together into a continuous con nection, the said swage connection comprising two identical swaged sections which are adjacent to and separated by a non-swaged section,

the latter being disposed so as to surround solely the said tapering wal section and a portion of the adjoining larger axial bore thereby providing a non-swaged section substantially less in length than either ofthe adjoining swaged sections, and said nose portion and bared portion of the conductor bci lg swaged together into a continuous electrical connection, said last mentioned swage being formed in close proximity to the said skirt portion.

5. The method of uniting in swaged relation the skirt portion of an electrical terminal to an insulated electrical conductor having a bared end, said skirt portion having an initially cylindrical shaped outer surface of uniform diameter throughout its entire length, comprising, first, disposing the bared and insulated parts of the conductor in axially formed recesses in the skirt portion, and then swaging the said skirt portion and both the bared and insulated parts of the conductor by forming two identical polygonally shaped sections and a single non-swaged section separating the said polygonally shaped sections, the said non-swaged section wholly surrounding a tapering section interconnecting the said axially formed recesses thereby providing a. non-swaged section substantially less in length than either of the adjoining swaged sections.

CLAIR D. LAKE. 

